Incidence and risk factors of pulmonary atelectasis in mechanically ventilated trauma patients in ICU: a prospective study

Aim: The aim of the study was to obtain information about the incidence and risk factors for pulmonary atelectasis in mechanically ventilated patients in the trauma ICU (TMICU). Pulmonary atelectasis is a common complication leading to serious lung dysfunction in patients in the TMICU and early identification of patients at risk is important for their effective management. Methods: All trauma patients admitted to the TMICU with mechanical ventilation for more than 1 day were included in a prospective 12-month study. Pulmonary atelectasis was diagnosed from chest radiographs by a critical care doctor and radiologist. Results: A total of 405 trauma patients were identified and data from 338 patients analyzed showing the incidence of pulmonary atelectasis to be 14%. Multivariate analysis revealed significant risk factors to be chest injury with an adjusted odds ratio (AOR) of 102.8, abdominal injury (AOR: 4.6), surgical intervention (AOR: 8.4), comorbidity (AOR: 13.7), Acute Physiology and Chronic Health Evaluation II score (APACHE II) of at least 15 (AOR: 4.8), sedation of at least 7 days (AOR: 7.5) and mechanical ventilation of at least 9 days (AOR: 3.43). Patients with chronic pulmonary disease tended to have higher risk for pulmonary atelectasis (AOR: 8.8). Patients with pulmonary atelectasis had longer stays in TMICU (P< 0.001) and higher mortality (P = 0.013). Conclusion: The incidence of pulmonary atelectasis in TMICU in Thailand is comparable with that of the developed world. Pulmonary atelectasis is particularly associated with chest trauma, whereas abdominal injury, APACHE II of at least 15, surgery, comorbidity and prolonged mechanical ventilation are also significant risk factors. Early interventions to prevent or treat pulmonary atelectasis in these patients may improve outcome and shorten their stay in the TMICU and hospital.